Persica Pharmaceuticals presents antibiotic exposure-response analysis at the International Society of Pain & Neuroscience (ISPN) Annual Conference

London, UK, 22 October 2026 - Persica Pharmaceuticals Limited (“Persica”), a clinical-stage biotechnology company developing PP353, a targeted, non-opioid treatment for vertebrogenic Lumbar Back Pain (vLBP), today announces presentation of a poster at the Annual Conference of the International Society of Pain & Neuroscience (ISPN) in Amsterdam on 22 October 2026.

Title: ‘Intradiscal antibiotic exposure correlates with clinical outcomes in patients with CLBP and Modic changes’
Authors: Chris Gilligan, Duncan McHale, Lloyd Czaplewski

The analysis addresses the question of why antibiotic studies in patients with vertebrogenic lumbar back pain (vLBP: chronic Low Back Pain with Modic changes) appear to report variable clinical outcomes. These studies differed by antibiotic dose, schedule, duration and route of administration, which may have led to different levels of drug reaching the site of infection in the disc. In the PK/PD modelling analysis, Persica examined published oral and intradiscal antibiotic studies in these patients and found a strong exposure-response relationship across studies, supporting a coherent understanding that the clinical benefit is correlated with antibiotic exposure in the disc. Differences in reported clinical outcomes may be explained by differences in estimated intradiscal antibiotic exposure. The manuscript has been submitted to the European Spine Journal and is available from Research Square preprint server¹.

PP353 is a targeted, intradiscal, non-opioid therapeutic for patients with vLBP. The Company's randomized, double-blind sham-controlled Phase 1b trial, published in The Lancet's eClinicalMedicine in February 2026, showed that PP353 produced statistically significant and durable improvements in pain and disability over 12 months, along with reduced use of pain medication, including opioids.

Persica continues to engage with potential strategic partners and investors to support the execution of the registrational programme required to bring PP353 to patients.

ENDS

For further information:
ICR Healthcare - Tracy Cheung, Chris Welsh, Emily Johnson
persica@icrhealthcare.com

About Persica Pharmaceuticals

Persica Pharmaceuticals is a clinical-stage biotechnology company developing PP353, a potentially disease-modifying, non-opioid treatment for vertebrogenic Lumbar Back Pain (vLBP), a common type of chronic Low Back Pain (cLBP) associated with Modic type changes, which represents approximately 15% of cLBP patients. Modic changes are a sign of inflammation, visible on MRI at the vertebral endplate adjacent to a degenerate lumbar disc. PP353 is a patented, targeted intradiscal antibiotic delivered directly to the site of disease. It is designed as an alternative to long-term analgesic use, including opioids, and addresses an underlying cause of vLBP rather than just the symptoms. Persica is seeking a strategic partner or investor to progress PP353 into registrational Phase 3 trials.

About PP353

PP353 is a non-opioid intradiscal therapy in development for vLBP, a precisely defined condition affecting an estimated 10 million patients in the US and Europe. PP353 is uniquely formulated to deliver linezolid, a well characterised antibiotic, directly into the affected intervertebral disc. Two administrations of PP353, four days apart, provide the necessary antibiotic exposure within the disc in order to target the low bioburden bacterial infection and treat the underlying cause of vLBP.

PP353 is a novel formulation of linezolid powder in a thermosensitive vehicle that is liquid at room temperature but increases in viscosity when injected at the site of disease and warmed to body temperature, thereby preventing leakage into adjacent tissue. PP353 also contains a radio-opaque dye, allowing physicians to confirm correct placement using image guidance. 

About vertebrogenic Lumbar Back Pain

Vertebrogenic Lumbar Back Pain (chronic Low Back Pain with Modic Type changes) represents approximately 15% of all cLBP cases, affecting around 10 million patients in the US and EU. vLBP patients can be easily identified with MRI and typically suffer moderate to severe persistent pain and disability for more than six months, with limited relief from current standard of care, which includes physiotherapy and analgesia such as opioids. Other treatment options provide only limited short-term relief or involve invasive, irreversible nerve ablation, neither of which addresses the suspected underlying cause of the pathology.

¹ https://doi.org/10.21203/rs.3.rs-10748663/v1